Common Questions about Lakes

How can I find out about the water quality of my lake?
Alberta Environment monitors the water quality of a number of lakes and reservoirs across the province. Due to the large number of water bodies, the department is unable to check every lake every year. Surface water monitoring and more intensive studies are also conducted with volunteer groups, industries and researchers. All water quality data are verified and stored in a central Water Database System and may be obtained by contacting: swq.requests@gov.ab.ca. For common water quality parameters, including water clarity, conductivity, pH, alkalinity, nutrients, and ion chemistry, raw and summary data reports for many of Alberta's lakes may be found on the " Online Surface Water Quality Reports" web page. If you would like to discuss any issues or concerns you may have regarding a specific lake, contact us at AENV-Web.SWQ@gov.ab.ca.

What are algae?
Algae are a diverse group of aquatic plants that form an important component of aquatic food chains. Many species float or are suspended in water (called phytoplankton) while others grow attached to a submerged substrate including rocks, plants, sediment and animals. Algae range extensively in size and shape, from microscopic, single-celled organisms to colonial species that resemble larger plants. Most algae obtain their nutritional needs directly from the water itself. Primary nutrients include nitrogen, phosphorus and carbon. Algae serve as a vital food source for microscopic animals, which in turn provide food for fish and other aquatic life.

What are cyanobacteria?
Cyanobacteria is a modern term used to describe a group of bacteria that, in the same fashion as algae and plants, convert sunlight and nutrients into energy required for growth and reproduction. Because they share many similarities in overall appearance, nutrient requirements, and habitat with algae, cyanobacteria were historically classified as algae and are still commonly referred to as blue-green algae. More than 100 species of cyanobacteria have been recorded in Alberta. Like algae, some species of cyanobacteria are suspended in water while others grow attached to submerged substrates. Some are microscopic, single-celled organisms and many others form large colonies easily seen in the water. Though they coexist with algae, cyanobacteria possess adaptations, such as the ability to use atmospheric nitrogen for growth, that often allow them to out-compete algae. This gives cyanobacteria a competitive advantage in nitrogen-poor lakes. Most species also have the ability to regulate buoyancy in order to position themselves at depths with optimum sunlight for growth. As a result, cyanobacteria grow extremely well during the warm summer months in Alberta's nutrient-rich lakes.

Cyanobacteria impart noxious odours and disagreeable tastes to water and fish, and can result in depletion of dissolved oxygen in the water when they decay, leading to winter and summer fish kills. More troublesome is the fact that several common species are known to produce potent liver and/or nerve toxins. These toxins have been linked to deaths of livestock, pets and wildlife, as well as mild to severe illness in humans consuming contaminated water. For further information on cyanobacterial toxicity, see “Problems and Issues ” FAQ and the “Cyanobacterial Toxicity” brochure.

Why does my lake turn green?
Phosphorus and nitrogen are important nutrients for the growth of algae and cyanobacteria. For most lakes, these nutrients enter primarily from their surrounding watershed. Because nutrient-rich sedimentary bedrock and soils exist throughout much of Alberta, our lakes tend to contain naturally elevated concentrations of phosphorus and nitrogen dissolved within them. Once in a lake, nutrients can remain for some time and may cycle annually or even more often. For instance, phosphorus is released from the bottom sediments of lakes into overlying water during periods of oxygen depletion. This deep, phosphorus-enriched water can mix with shallow surface waters during windy periods or during spring and fall turnover, in effect fertilizing the lake. The results are often excessive growth of both cyanobacteria and algae, which can make the lake water look green and murky. When climatic conditions are right, cyanobacteria may accumulate at the water's surface in what is known as a cyanobacterial (blue-green algal) bloom. Though natural to some extent, activities in and around lakes that further increase nutrient loading (including cottage and residential development, agriculture, forestry and other industry), can exacerbate the problem. For further information on cyanobacterial blooms, see the “Cyanobacterial Blooms in Surface Waters” brochure.

What are macrophytes?
This is a general term for large aquatic plants. Often referred to as "weeds", these plants are common in Alberta's shallow productive lakes, and are a key component of lake ecosystems. Most are rooted plants that obtain their nutrients from sediments in the lake or river bottom. Some, such as cattails, emerge from the water, while others, such as pondweeds, live submerged under the water. A few types, like water lilies, float on the surface.

Why are macrophytes considered important?
Macrophytes provide oxygen, food and shelter for fish. They also provide spawning and rearing habitat. A number of fish, including the Northern Pike, attach their eggs to the stalks of emergent and submerged vegetation. Many large animals, including moose, feed on macrophytes. Macrophyte beds provide hiding and nesting sites for birds, amphibians, reptiles and other animals. In addition to their importance to fish and wildlife, macrophytes help stabilize shorelines and lake bottoms, reduce erosion by suppressing wave action, and may help maintain good water quality by taking up nutrients which would otherwise encourage algal growth.

Can I cut the weeds in front of my cottage?
Beds of aquatic plants are considered to be fish habitat and are protected under the Canada Fisheries Act. Except for very small-scale hand removal of aquatic vegetation, the removal of aquatic plants from the bed of the lake requires a permit from Public Lands.

Why do we get "itchy" after swimming in our lake?
Unfortunately, swimmer's itch is a common problem in many Alberta lakes, and particularly in those with extensive weed beds and large waterfowl populations. The "itch" is caused by the intermediate stage of a parasite that normally cycles between ducks and snails. Humans come in contact with the parasite while swimming. Although the parasites die, they cause an allergic reaction in the skin, and hence the itch. Be sure to shower well and towel down vigorously after swimming if you suspect your lake has these organisms.

Is it safe to eat the fish from my lake?
Limited data are available to define contaminant levels in fish tissue in Alberta lakes. Not all lakes have been tested. Any lake for which contaminant levels in fish have been detected above safe consumption levels are listed in the annual Alberta Guide to Sport Fishing Regulations.

What causes the water level in my lake to rise and fall?
Spring runoff and early summer rains usually produce the greatest volumes of inflow in Alberta, while lowest runoff occurs in fall. Lake levels tend to reflect these patterns, but their responses can also be moderated by long-term climatic factors as well as by dams or weirs on the outflow. Groundwater inflows and outflows can also be important factors, but difficult to measure. The activities of beavers can play a surprisingly large role in controlling lake inflows and outflows! Click here for more information on lake levels.

How can I protect my lake?
One of the best ways is for all of the stakeholders in the watershed to work together to identify and correct nutrient sources that may be contributing to water quality problems. Many lake stewardship societies have been formed in Alberta in recent years, and there is a large body of scientific knowledge now available. On several lakes, watershed residents have made excellent progress through cooperative efforts. Efforts to control phosphorus will often help to control other water quality factors such as nitrogen, suspended sediments and bacteria. Become involved and informed! See the LINKS page for many informative websites.